Play toys for animals, and particularly dogs, have been available for years in various sizes and configurations, each designed to provide jaw exercise and to enhance the animals' interest in playing with the toy. Enhanced interest in the toy may occur by giving it a physical configuration which will bounce in odd directions when tossed onto the floor or ground. Also interest in a pet toy can be enhanced by providing food treats in the pet toy. Many pet toys provide one or both of these features with varying success. Examples of such toys are found in U.S. design Pat. Des. No. 234,789 and Des. No. 234,790 to Rosenberg, each entitled "Sounding Toy For Pet Animal", and U.S. design Pat. Des. No. 256,958 to Markham, entitled "Pet Toy". This latter pet toy is hollow and has an irregular outer configuration and provides substantial jaw exercise for the animal.
A further example of such prior art pet toys is U.S. Pat. Re. No. 34,352 to Markham, entitled "Therapeutic Pet Toy". This pet toy has an irregular outer configuration and a central core extending therethrough. A series of longitudinally spaced peripheral grooves are provided which have inwardly projecting lips for cleaning the teeth of the animal. The hollow core facilitates deformation of the pet toy with the animal bites into the grooves. The resistance of the pet toy to deformation provides exercise for the animal's jaw.